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Textile flammability research since 1980 – Personal challenges and partial solutions
No full textThis paper reviews the changing textile flammability research themes within the author’s research group over the last 35 years and which reflect those of the academic and research communities often influenced by industrial and societal pressures. For instance, ignition studies undertaken in the early 1980s together with the effect of textile fabric structural variables reflected academic contemporaneous interests as well as those related to real hazards posed, for example, by nightwear fabrics. Also, work undertaken to study flame retardant mechanisms, especially on cotton substrates, reflected the need for commercial interests to more fully understand their chemical treatments largely developed during the 1960-1970 period.During the subsequent 1980 period, the ecotoxicological concerns regarding flame retardants in general started to develop which continue with even greater vigour at the present time.Thus research effort focused on developing low or zero formaldehyde treatments for cotton and alternatives to bromine-based flame retardants present in back-coatings applied to furnishing fabrics which also promoted interest in the study of novel intumescents. By the 1990s, the demonstration of the potential of nanocomposite polymers with improved fire performance raised the possibility of novel textile flame retardant developments with improved environmental sustainability. More recently, nanotechnological engineering of fibre surfaces to promote improved substrate flame retardancy has created a significant literature.In conclusion, it is evident that while most of this research has improved scientific knowledge, its translation into novel commercial opportunity has been more elusive and this will probably remain the case as we move into the next ten years or so where the environmental challenges of reducing real or apparent ecotoxicological properties of flame retardant textiles remain
Flame retardant textiles in transport (land, sea and air).
No full textAs land, marine and air transport becomes more safety conscious, achieves higher velocities and capacities and increasingly uses composites within their structural components as a means of weight reduction, so the potential flammability of all materials used to construct them increases in risk. Furthermore, the desire for increased passenger comfort ensures that textiles in seating, other furnishings, floorcoverings and décor are part of the transport environment. Not surprisingly, since transport crosses international borders, fire regulations are becoming increasingly global in character.This chapter identifies the key textile-related fire risks in transport and relates these to the general need for international regulations and fire standards. It outlines the regulations and standards relating to the use of textiles in land, marine and air commercial transport. It describes the major uses of textiles and composites such as seating of which they are a part, their respective fire risks, test regimes and favoured textile materials
Theorisations of leisure in inter-war Britain
No full textThe National Conference on the Leisure of the People in 1919 marked the emergence of a public discourse on the nature and purpose of leisure in inter-war Britain. One strand of this discourse saw leisure to be problematic as new forms of mass and passive entertainment, the 'enforced leisure' of unemployment and the right use of leisure became areas of social concern. Perceptive critics, however, conceptualised leisure as a social sphere in which a new and better post-war society could be built through a democratic 'new' leisure and the use of leisure as a vehicle for education in citizenship. Leisure was widely documented in contemporary social surveys and became valued by local councils of social service in developing social life and community identity on new housing estates. This paper argues that a new ontology of leisure was forged between the wars as the Victorian emphasis on rational recreation and private morality was superseded by an understanding of leisure as a social product of late modernity
Making shape memory polymers reprocessable and reusable by a simple chemical method
No full textWe have found that a group of shape memory polymers in the polyurethane family can be recycled for new use when their parent polymeric chains are fabricated with a small percentage of polyethylene glycol, and the products are subsequently reprocessed in N,N-dimethylformamide (DMF), a very commonly used organic solvent
Smart microgrippers for bioMEMS applications
No full textGrasping and manipulating small or micro-objects is critical for a wide range of essential biological applications, such as the assembly of small parts in microsurgery, nerve repair, and selective manipulation or separation of cells, microbes, localized cell probing, measurement etc. Different microgripping and releasing mechanisms have been reviewed and discussed in this chapter. Smart microgrippers or microcages based on the combination of highly compressively stressed diamond-like carbon (DLC) and electroplated Ni bimorph structures or SU8 polymer layer and shape memory thin films have been designed, simulated, fabricated, and characterized. Theoretical, simulation, and experimental results revealed that the radius of curvature of the bimorph layer can be adjusted by varying the DLC film stress and thickness ratio of the DLC to metal or polymer layers. The angular deflection of the bimorph structures can be adjusted by varying the finger length. The radius of curvature of the microcage is in the range of 20-100 mu m, suitable for capturing and confining micro-objects with similar sizes. The operation of this type of device is based on either (1) a large difference in thermal expansion coefficients of the DLC and the metal or polymer layers or (2) the shape memory effect. Electrical tests have shown that these microcages can be opened efficiently utilizing a power smaller than 20 mW and a frequency of 100 Hz
Comparative study on the synergistic effect of POSS and graphene with melamine phosphate on the flame retardance of poly(butylene succinate)
No full textFlame retardant poly(butylene succinate) (PBS) composites were prepared by melt blending PBS with melamine phosphate (MP), using graphene or polyhedral oligomeric silsesquioxanes (POSS) as synergists. The comparative study on the effect of POSS and graphene on the mechanical, thermal properties and flammability of flame retardant PBS was investigated. The addition of POSS or graphene further improved the LOI values of the flame retardant PBS, and V0 rating was obtained for the formulation containing 18 wt % MP and 2 wt% graphene. The incorporation of POSS and graphene reduced the crystallization of PBS, but improved the tensile strength. The presence of graphene exhibited superior thermal-oxidative resistance of the char layer compared to POSS, which effectively retarded the mass and heat transfer between the flame and the burning substrate, thus the heat release rate and total heat release of the flame retardant PBS composites containing graphene was significantly reduced during combustion